Question

Please guys help me my head is hurting!!!!!!!!

find x if 101 base x =17


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Answer 1

Write out the base-x expansion of
`101_x` :

`101_x` = 1 • x² + 0 • x¹ + 1 • x⁰

This number is equal to 17 (in base 10), so that

x² + 1 = 17

Solve this for x :

x² = 16

x = ±4

(Yes, negative bases are totally valid.)